Reversing and cut-off valve



(No Model.)

' F, CHASE.

RBVERSING AND 'GUT-OFP VALVE. No. 279,912. Patented June 26, 1883.

nmufruuuum F1' 5, 5 L

WII'NEESES.

UNITED STATES l PATENT OFFICE.

'rnANKcHAsn or BOSTON, MASSACHUSETTS.

RVERSING AND GUT-OFF VALVE.

SPECIFICATION lforming part of Letters Patent No. 279,912, dated June26, 1883.

AApplication tiled October 2. 1882 (No model.)

To all whom t may concern.-

Be it known that I, FRANK. CHASE, of Boston, in the county of Suffolkand State of Massachusetts, have invented certainnew and usefulImprovements in Reversing and Cut-Off Valves, of which the following isa specification.

The object of my invention is to provide a cheap, simple, and efficientvalve-motion, which may be driven by a single eccentric keyed to itsdriving-shaft, whereby the engine may be reversed in an easy andexpeditious manner; and

it consists in the construction, combination, and arrangement of adouble slide-valve, provided with two steam-passages and twoexhaust-passages, which operate in connection with a puppet-valve andcylinder having four steam' ports and an exhaust-port, as hereinaftermore fully described, and set forth in the claims.

Figure 1 representswa vertical section of a slide-valve and steam-portsembodying my in vention. Fig. 2 represents va similar view of the samewith the opposite extreme position of the slide-valve. Fig. 3 representsthe first position of the slide-valve with the valve-stein lengthened.Fig. 4 represents the opposite extreme position of the slide-valve withstem lengthened. Fig. 5 represents a top or plan view of valve-stem inits shortened position. Fig. 6 represents a vertical central section ofthe puppet-valve and governorvalve. Fig. 7

represents a vertical cross-section of the gov? ernorfvalve.

In order to construct a valve-motion which may be driven by a singleeccentric keyed to its driving-shaft, which shaft may be reversed, Iconstruct the cylinder (not shown) with four steam-ports, E, and anexhaust-port, M, which ports are adapted to be opened and closed by adouble slideLvalve provided with t`wo steampassages, N N5, and two`exhaust-passages, I"

P', and two plates, R It', which valve is also provided with anadjustable stem, S, having a screw-thread, T, connecting with a.corresponding threaded nut, U, attached to the end'of the eccentric-rodV in any suitable manner, so as to permit the said valve-stem S to berotated about its own axis, and thereby lengthen or shorten the samewhen desired to change the relative longitudinal position of the saidslidevalve to the actuating-eccentric O and steamports E E', therebycausing a direct opposite communication of Asteam to the piston, thusproducinga reverse 'motion of the crankshaft of the engine.

The operation of this valve and connections are as, follows: Referencebeing had, first, to

Fig. 1, steam being admitted into the passage N between the outer valveand inner valveV and thus prevents the escape of steam from the pressureside ofthe piston. In Fig. 2 is shown the same relative position of thevalve Vadmitting steam into the opposite end of the cylinder, in Figs. 1and 2 the valve being shown at the positions when at the extreme end ofthe stroke. It will be seen in Fig. 3 the said valve-stem S has beenlengthened, so as to cause the steam to enter from the said passage Nthrough the port E to the main piston, and exhaust through the port Eand passage I into the outlet M from opposite sides of the piston, asbefore, the said plate R covering the inner port, E, thereby preventingthe steam from escaping from the pressure side of the piston, as abovedescribed, referring to Figs. l and 2. In Fig. 4 is shown the oppositeposition of the valve, in which steam enters into the passage N betweenthe outer and inner valves, and is admitted through port E to the mainpiston, and exhausts from opposite sides of the piston through the twoports E and E and passage P into the outlet M.

It will be observed and understood that in Figs. land 2 are shown thevalve in its extreme travel with the valve-stem S in its shortenedposition, and in Figs. 3 and 4 the valve is shown in the sainepositions, the valve-stem S being` lengthened. In the first positions(shown by Figs. 1 and 2) the steanrports are opened and closed by themovement of the outer or external portion of the valve at such point inthe stroke of the piston as to cause the engine to run in one direction,and in the second positions (shown in Figs. 3 and 4) the steam-ports areopened and closed by the movement of the internal portion of the valveat such point in the stroke of the piston as to cause the engine toreverse, or to run in the opposite direction, thus accomplishing thedesired result. The

slide-valve D, being on its center covering all the ports, brings theopening J of the governor-valve L into position, so as to connect theports t and u, leading to the main eXhaust, and

thus relieve the upper end or top of the piston A of the pistonpuppet-valve77 B from any pressure. Consequently the pressure on theunder side of the said piston A will raise the said valve B (on accountof the differential area of the said piston and valve) from its seat F.Then the steam enters the steam-port C below the said valve B within theslide-valve D, when the steam is transmitted to the cylinder-ports E bythe movement of the said slide-valve D to the end of its stroke, duringwhich movement the small steam-port G is opened to the top of the pistonA, admitting steam to the upper end of the same, thereby overcoming thepressure of steam on the under side of the said piston-head Asufficiently to force the said valve B to its seat F, by which means thesupply of steam is cut off from the cylinder, and ,the piston is carriedto the end of its stroke by the expansion of steam contained therein. Atthe same time the lower end, H, of the said valve is forced against thesteam contained within the dash-pot 7 I, (having a suitable relief oroutlet, 1),) whereby it is cushioned in its downward movement; and itsupward end is similarly cushioned by the piston-head A in its upwardmovement closing the exhaust-port J just before the piston completes itsstroke.

rlhe governor-valve L is formed pointed or V-shaped at its forwardend,so as to permit the said port G to open variably through the varyinglongitudinal movements of the said governor-valve L, which may beoperated by any suitable means, either by hand, or by a commonball-governor, so as to close Vthe said port G variably, whereby avariable degree of expansion of steam in the cylinder is produced.

It will be observed that the governor-valve L is made double, as regardsits width, and is provided with an extra opening, J, so as to connectthe said ports t and u when the valvestem is lengthened, as shown inFigs. 3 and 4.

Having thus described my invention, what I claim is- 1. A doubleslide-valve having two steampassages, two exhaust-passages, and twoplates adapted to operate with a steam-cylinder having four steam-portsand an exhaust-port, as and for the purposes set forth.

2. The combination, with the double slidevalve having two steampassages,two eX- haust-passages, and two plates adapted to operate with asteam-cylinder having four steamports andan exhaust-port, of theadjustable valve-stem, as and for the purposes set forth.

3. The combination, with the double slidevalve having two-steampassages, two eX- haust-passages, and two plates, of theadjustable valve-stem S, connected with a single eccentric, and adaptedto reverse the engine, substantially as described, as and for thepurposes set forth.

4. rlhe combination of the governor-valve, piston puppet-valve, doubleslide-valve, and adjustable valvestem, substantially as described, asand for the purposes set forth.

FRANK CHASE. lVitnesses:

SYLvENUs WALKER, WV. B. MARBLE.

